#54 - Added support for RFC5988 link headers.

Introduced new Links container element to group a list of links and allow parsing an RFC5988 compatible String representation of links into it. The parsing mechanism is currently regarding the rel attribute only.

Added valueOf(…) factory methods to allow Spring MVC to pick the types up out of the box.

src/test/java/org/springframework/hateoas/LinksUnitTest.java

@@ -0,0 +1,63 @@
+/*
+ * Copyright 2013 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.hateoas;
+
+import static org.hamcrest.CoreMatchers.*;
+import static org.junit.Assert.*;
+
+import java.util.Arrays;
+
+import org.junit.Test;
+import org.springframework.util.StringUtils;
+
+/**
+ * Unit test for {@link Links}.
+ * 
+ * @author Oliver Gierke
+ */
+public class LinksUnitTest {
+
+	static final String FIRST = "</something>;rel=\"foo\"";
+	static final String SECOND = "</somethingElse>;rel=\"bar\"";
+
+	static final String LINKS = StringUtils.collectionToCommaDelimitedString(Arrays.asList(FIRST, SECOND));
+
+	static final Links reference = new Links(new Link("/something", "foo"), new Link("/somethingElse", "bar"));
+
+	@Test
+	public void parsesLinkHeaderLinks() {
+
+		assertThat(Links.valueOf(LINKS), is(reference));
+		assertThat(reference.toString(), is(LINKS));
+	}
+
+	@Test
+	public void skipsEmptyLinkElements() {
+		assertThat(Links.valueOf(LINKS + ",,,"), is(reference));
+	}
+
+	@Test
+	public void returnsNullForNullOrEmptySource() {
+
+		assertThat(Links.valueOf(null), is(Links.NO_LINKS));
+		assertThat(Links.valueOf(""), is(Links.NO_LINKS));
+	}
+
+	@Test
+	public void getSingleLinkByRel() {
+		assertThat(reference.getLink("bar"), is(new Link("/somethingElse", "bar")));
+	}
+}